In order to cover the power required within certain fields of use a series of prime mover sizes is usually needed. This means a high cost per unit, and also often an expensive stock-keeping of spare parts. On many occasions a "package" embodiment is further called for, for instance in mobile compressor and electric generator units, where a compact, lightweight prime mover is required. The same applies to an increasing demand for stationary plants.
By using gas turbine units built as modules in a standard size it is possible to cover a wide power demand. In this manner the initial cost per unit will be low, while simultaneously stock-keeping of spare parts can be minimized. A very compact and lightweight plant is obtainable for use for various purposes, such as operating
electric generators PA1 heat pumps PA1 compressors PA1 pumps, as well as in PA1 total energy systems. PA1 75-300 kW in steps of 75 kW PA1 100-400 kW in steps of 100 kW PA1 150-600 kW in steps of 150 kW.
A rapid supply of electric current in case of breakdown of the power mains is vital for hospitals, shopping centers, big office buildings, but also for isolated built-up areas. A gas turbine does not need any supply of cooling water, which in case of need makes it preferable to the internal combustion engine.
A gas turbine is very silent and can easily, due to its small dimensions, be built into a "package" plant, and can be fully sound insulated.
On many occasions it is important and economically favourable that industrial engines can use various kinds of fuels. A gas turbine can advantageously use gaseous, liquid as well as solid fuels.
By the present invention it is possible to cover wide power requirements by using a common basic unit (a gas turbine), and mounting 1, 2, 3 or 4 such units in a plant. With a basic unit having, say, a normal output of 100 kW it is easy to provide a version of, say, 75 kW output (reduced turbine inlet temperature) or a 150 kW-unit (uprated version with certain components made of ceramic material). The first version can be fully identical with the basic unit, while the second one can be comparable up to 80 or 90%.
With these standard modules it is possible to cover the following power requirements.
It is of course possible to combine units with varying output rates, and in such manner it will be possible to cover the field 75-600 kW in small steps.
In various versions the gas turbine is built in a non-regenerative and a regenerative embodiment, respectively, to make possible an adjustment towards high power density, or high thermal efficiency, respectively. The power density at a non-regenerative version may be 2 to 3 times as high as with a regenerative version. In certain applications for military purposes, as well as for use on marine oil drilling rigs the power density is a very important parameter. Even a regenerative version is, however rather compact compared with other engines available on the market.
On an oil drilling rig it is, for example, advantageous to be able to operate the power units upon gas or upon crude oil. A gas turbine may use both kinds of fuels in the same combustor if this is dimensioned for dual-fuel operation. Either fuel, or both fuels simultaneously may be used in order to provide a maximum of availability. The turbine is advantageously designed with simple can-type combustor, but on occasions an annular one may be useful.
By substituting the combustor and the fuel system in gas turbines according to the invention, which is easily performed, solid fuels (for instance coal, wood, peat), or slurries (coal/oil, coal/water or coal/oil/water) may be used instead of the gaseous or liquid fuels.
In a basic concept a gas turbine unit may be largely composed of standard components used in the car industry in order to make possible the introduction of large series. It is for instance possible to use rotors and bearings from turbochargers and lamella-clutches from automatic gear boxes.